Plumb firing passive event listeners.

content/renderer/input/render_widget_input_handler.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/input/render_widget_input_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <utility>
 
@@ skipping 173 matching lines @@
       ignore_ack_for_mouse_move_from_debugger_(false) {
   DCHECK(delegate);
   DCHECK(widget);
   delegate->SetInputHandler(this);
 }
 
 RenderWidgetInputHandler::~RenderWidgetInputHandler() {}
 
 void RenderWidgetInputHandler::HandleInputEvent(
     const WebInputEvent& input_event,
-    const ui::LatencyInfo& latency_info) {
-  // TODO(dtapuska): Passive support not implemented yet crbug.com/489802
-  bool passive = false;
+    const ui::LatencyInfo& latency_info,
+    bool passive) {
   base::AutoReset<bool> handling_input_event_resetter(&handling_input_event_,
                                                       true);
   base::AutoReset<WebInputEvent::Type> handling_event_type_resetter(
       &handling_event_type_, input_event.type);
 
   // Calls into |didOverscroll()| while handling this event will populate
   // |event_overscroll|, which in turn will be bundled with the event ack.
   scoped_ptr<DidOverscrollParams> event_overscroll;
   base::AutoReset<scoped_ptr<DidOverscrollParams>*>
       handling_event_overscroll_resetter(&handling_event_overscroll_,
@@ skipping 142 matching lines @@
               gfx::ToFlooredPoint(touch_event.touches[i].position))) {
         ack_result = INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
         break;
       }
     }
   }
 
   // Send mouse wheel events and their disposition to the compositor thread, so
   // that they can be used to produce the elastic overscroll effect on Mac.
   if (input_event.type == WebInputEvent::MouseWheel) {
-    delegate_->ObserveWheelEventAndResult(
-        static_cast<const WebMouseWheelEvent&>(input_event),
-        event_overscroll ? event_overscroll->latest_overscroll_delta
-                         : gfx::Vector2dF(),
-        processed != WebInputEventResult::NotHandled);
+    const WebMouseWheelEvent& wheel_event =
+        static_cast<const WebMouseWheelEvent&>(input_event);
+    if (wheel_event.canScroll) {

[tdresser, 2016/01/26 16:34:37]

The canScroll check is unrelated to the rest of your patch, right?

[dtapuska, 2016/01/26 16:53:15]

Ultimately yes; for passive wheel listeners; canScroll is always false; but it
was taking this code path which actually is unintended.

[tdresser, 2016/01/26 18:45:42]

Acknowledged.

+      delegate_->ObserveWheelEventAndResult(
+          wheel_event,
+          event_overscroll ? event_overscroll->latest_overscroll_delta
+                           : gfx::Vector2dF(),
+          processed != WebInputEventResult::NotHandled);
+    }
   }
 
   bool frame_pending =
       widget_->compositor() && widget_->compositor()->BeginMainFrameRequested();
 
   // If we don't have a fast and accurate Now(), we assume the input handlers
   // are heavy and rate limit them.
   bool rate_limiting_wanted = input_event.type == WebInputEvent::MouseMove ||
                               input_event.type == WebInputEvent::MouseWheel;
   if (rate_limiting_wanted && !start_time.is_null()) {
     base::TimeTicks end_time = base::TimeTicks::Now();
     total_input_handling_time_this_frame_ += (end_time - start_time);
     rate_limiting_wanted =
         total_input_handling_time_this_frame_.InMicroseconds() >
         kInputHandlingTimeThrottlingThresholdMicroseconds;
   }
 
   TRACE_EVENT_SYNTHETIC_DELAY_END("blink.HandleInputEvent");
 
   // Note that we can't use handling_event_type_ here since it will be overriden
   // by reentrant calls for events after the paused one.
   bool no_ack = ignore_ack_for_mouse_move_from_debugger_ &&
                 input_event.type == WebInputEvent::MouseMove;
-  if (WebInputEventTraits::WillReceiveAckFromRenderer(input_event) && !no_ack) {
+  if (passive) {
+    // Passive means it was ack'd already by the InputHandlerProxy
+    // so let the delegate know the passive event has been handled.
+    delegate_->PassiveInputEventHandled(input_event.type);
+  } else if (WebInputEventTraits::WillReceiveAckFromRenderer(input_event) &&
+             !no_ack) {

[tdresser, 2016/01/26 16:34:37]

Is this indentation correct?

[dtapuska, 2016/01/26 16:53:15]

Done.

     scoped_ptr<InputEventAck> response(new InputEventAck(
         input_event.type, ack_result, swap_latency_info,
         std::move(event_overscroll),
         WebInputEventTraits::GetUniqueTouchEventId(input_event)));
     if (rate_limiting_wanted && frame_pending && !widget_->is_hidden()) {
       // We want to rate limit the input events in this case, so we'll wait for
       // painting to finish before ACKing this message.
       TRACE_EVENT_INSTANT0(
           "renderer",
           "RenderWidgetInputHandler::OnHandleInputEvent ack throttled",
@@ skipping 108 matching lines @@
   if (pending_input_event_ack_) {
     TRACE_EVENT_ASYNC_END0("input",
                            "RenderWidgetInputHandler::ThrottledInputEventAck",
                            pending_input_event_ack_.get());
     delegate_->OnInputEventAck(std::move(pending_input_event_ack_));
   }
   total_input_handling_time_this_frame_ = base::TimeDelta();
 }
 
 }  // namespace content